• printf 출력을 UART로 변경
• Core/Src/syscalls.c

__attribute__((weak)) int _write(int file, char *ptr, int len)
{
  (void)file;

  HAL_UART_Transmit(&huart1, (const uint8_t *)ptr, len, 100);

  return len;
}

void apMain(void)
{
  uint32_t cnt = 0;

  while(1)
  {
    logPrintf("test %ld\\n", cnt++);
    delay(500);
  }
}